At the very least, WARC could have been used as the container ("tar") format after the preamble of Gwtar. But even there, given that this format doesn't work without a web server (unlike SingleFile, mentioned in the article), I feel like there's a lot to gain by separating the "viewer" (Gwtar's javascript) from the content, such that the viewer can be updated over time without changing the archives.

I certainly could be missing something (I've thought about this problem for all of a few minutes here), but surely you could host "warcviewer.html" and "warcviewer.js" next to "mycoolwarc.warc" "mycoolwrc.cdx" with little to no loss of convenience, and call it a day?

You could potentially use WARC instead of Tar as the appended container, sure, but that's a lot of complexity, WARC doesn't serialize the rendered page (so what is the greater 'fidelity' actually getting you?) and SingleFile doesn't support WARC, and I don't see a specific advantage that a Gwtar using WARC would have. The page rendered what it rendered.

And if you choose to require separate files and break single-file, then you have many options.

> surely you could host "warcviewer.html" and "warcviewer.js" next to "mycoolwarc.warc" "mycoolwrc.cdx"

I'm not familiar with warcviewer.js and Googling isn't showing it. Are you thinking of https://github.com/webrecorder/wabac.js ?